Electron-discharge device



A. W. HULL.

ELECTRON DISCHARGE DEVICE.

APPLICATION FILED NOV. 13. 1916.

1,387,985. Patented Aug. 16,1921.

I'I H I I I I I l l l l Inventor: 'JIlbert. W. Hull,

His fittovneg.

UNITED STATES PATENT orrice.

ALBERT W. HULL, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELNCTRIC COMPANY, A CORPORATION OF NEW YORK.

To all whom it may concern Be it known that I, ALBERT W. HULL, a citizen of the. United States, residin at Schenectady, county of Schenectady, tate of New York, have invented certain new and useful Improvements in Electron-Discharge Devices, of which the following is a specification.

My present invention relates to the construction and operation of electron discharge devices and particularly devices which are suitable for use as relays for amplifying variable currents or for controlling the amplitude of the current flow in an electric circuit in accordance with variations in the amplitude of the current flowing in a controlling circuit.

The novel features which I believe to be characteristic of my invention are 'set forth with particularity in the appended claims. The invention itself, however, both as to its construction and mode of operation together with the objects and advantages thereof will best be understood by reference to thelfollowing description taken in con nection with the accompanying drawing in;

which Figure 1 shows an elevation of a device embodying my invention; Figs. 2 and 3 are diagrammatic representations of the movement of the electrons in such a device under different conditions of operation and Figs. 4 and 5 show circuit connections in which my device may be utilized to advantagem p The device shown in Fig. 1 consists of a highly evacuated envelop 1 provided with a linear filamentary cathode 2 connected to leading-in conductors 3 and 4 for supplying current for heating it to incandescence. This cathode is preferably surrounded with a grid-like structure which is coaxial therewith and in the present illustration consists of fine wires 5 wound back and forth between the circular supports 6. This structure serves as anode for the device and is connectedto a leading-in conductor 7. Surrounding the cathode and anode and coaxial therewith is a third electrode consisting of a metal cylinder 8connected to the leading in wire 9. It will be observed that in the form of my invention illustrated the electrodes arearranged in circular symmetry to one another, that is, they are so arranged that the active surfaces of the electrodes are substantially surfaces of revolution about a nnno'raou-msenaaen DEVICE.

Specification of Letters Patent. Patent ed Aug. 16,, 1921.

Application filed November 13, 1916. Serial No. 130,990.

common axis which, as in the construction illustrated, is preferably'the major aXis of the envelop. The envelop 1 should preferably be exhausted to such a degree of vacuum that whenpotentials of the magnitude desired for operation are supplied to the positive with respect to the cathode a por tion of the electrons will pass between the wires 5 of the anode and strike the third electrode, the paths of such electrons being indicated by dotted lines 11 in Fig. 2. The velocity with which these electrons will strike the third electrode will depend upon the potential difference between it and the cathode. If this potential is increased the velocity will increase until the electrons striking the third electrode are able by their impact to liberate secondary electrons. These secondary electrons leaving the third electrode will be attracted to the more positive anode. As the potential of the third electrode is increased a point will finally be reached at which the rate of increase in the emission of secondary electrons exceeds the rate of increase in primary electrons received and the current in the external circuit between cathode and third electrode will begin to decrease. As the potential is further increased a point may be reached at which the number of secondary electrons leaving the third electrode is just equal to the number of primary electrons which strike it, that is, each electron that strikes liberates on an average one secondary electron. No currentwill then flow in the external circuit between the cathode and third electrode. If the potential of the third electrode is further increased the number of secondary electrons given off ,becomes greater than the number of primary electrons received, and as a result the tliird electrode loses electrons, the current in thecircuit between cathode and third electrode refrom the cathode.

' versing in direction. In brief, as the potential in the circuit between cathode and third electrode increases the current increases for a time and then decreases;that is,there is a certain range over which the circuit has a.

negative resistance characteristic. For a more complete descriptlon of the characteristics of such a device reference may be had to my co-pending application, Serial. No. 47,938, filed August 30, 1915. In that application I have shown that such' a device may be employed for various useful purposes by controlling the current between cathode and third electrode by varying the potential applied to the third electrode. One of the ob-' in radial linesthey will tend to move inspiral lines tangentiallyto the anode as indicated by the dotted lines 12, in Fig. 3. As the strength of the magnetic field is increased these lines contract toward the cathode and if:- the field is made strong enough it will be apparent that ,allof the electrons will be intercepted by the wires 5 andnone of them will re ch the third electrode 8. If, however, the magnetic field acting upon ,the electrons is varied between zero and the value at which none of the electrons will reach the third-electrode, a vari- -able number of-electrons will be able to ass between the grid wires 5 and reach the t ird electrode .8. The magnetic field for controlling the flow-jot electrons in this way may be furnished bya winding 13 upon a spool14 surrounding. the tube.

In the arrangement shown in'Fig. 4 I have shown-diagrammatically an organization whereby. the-device described may be utilized for" amplifying variable currents. :As here indicated the cathode 2 is supplied with current by'the battery 15 and the battery. 16 supplies a definite positive potential to the anode 5. -A smaller positive potential is applied tothe third electrode 8 by the portion 17 of battery-16. The variable currentslwhich are to be amplified are caused to flowihrough the winding 13'. With the connectionshown the current flowing in the conductor l8 connecting the cathode and third electrode will vary in accordance with thevariations inthe current flowing in the controlling -winding 13. This variable current in conductor18 may utilized for the operation of any desired indicating apparatusor a resistance 19 may be inserted in the circuit and the variations in potential across this resistance may be employedfor the operation of the desired apparatus.

In another copending application, Serial No. 60,402, filed November 8, 1915, I have explained how a device having the negative resistance characteristic described may be utilized for producing high frequency oscillations by including an inductance shunted by capacity in the circuit between cathode and third electrode. If the present device is organized in such a way as to produceoscillations the amplitude of the oscillations produced can conveniently be controlled by varying the amplitude of the current flowing in the controlling winding. Such an arrangement is indicated in Fig. 5

in which a variable inductance 20 shunted by a variable capacity 21 is included in the circuit between cathode and third electrode. The current in winding 13 for controlling the amplitude of the oscillations produced may be derived from the secondary of the transformer 22 through the primary 23 of which current is caused to flow from the local circuit of a telephone transmitter 24:. By coupling inductance 20 with the antenna 25 -continuousoscillations will be impressed upon the antenna which vary in amplitude in. accordance with the variations in the current through the telephone transmitter 24.

While I have shown and described a single form of my device, my invention is not limited to the particular form illustrated as it will be apparent that many modifications in the'shape and arrangement of the various parts may be made without "emission of secondary electrons. from the third electrode sufficient to give the device a negativeresistancecharacteristic, and subjecting the stream of electrons to the action of a variable magnetic field thereby varying the number of primary electrons which can reach the third electrode;

2. The method of operating an electron discharge device 7 comprising an electron emittin cathode, an anode and a third electrodew ich consists in'applying a constant positive potential to the anode, applying a positive potential to the third electrode of such a value'as to roduce'an emission of secondary electrons therefrom-sufficient to action of a magnetic field and thereby varying the number of electrons flowing between cathode and third electrode.

3. The method of operating an electron discharge device comprising an electron emitting cathode, an anode and a third electrode, which consists in applying a constant positive potential to the anode, applying asmaller positive potential to the third electrode to produce an emission of secondary electrons therefrom and subjecting the electrons to the action of a variable magnetic field.

4. The method of operating an electron discharge device comprising an electron emitting cathode, an anode and a third electrode, which consists in applying a. constant positive potential to. the anode, applying a positive potential to the third electrode of such a value as to give the device a negative resistance characteristic, and varying the current flow between cathode and third electrode by means of a variable magnetic field.

'5. The method of operating an electron discharge device comprising an electron emitting cathode, an anode and a third electrode, which consists in applying a constant positive potential to the anode, applying a positive potential to the third electrode of such a value as to give the device a negative resistance characteristic, and producing a magnetic field in a direction parallel to said cathode.

6.Ilhe method of operating an electron discharge device comprising an electron emitting cathode, a grid anode and a third electrode, which consists in roducing an emission of electrons from said cathode to said anode and third electrode, subjecting said electrons to the action of a magnetic field in such a way that they will move in spiral lines around said cathode and tangentially to said anode and thereby causing a greater number of electrons to be intercept-- ed by the anode than when the magnetic field 'is absent.

7. The method of amplifying a variable current which consists in producing an emission of electrons from a cathode to a grid anode and third electrode surrounding said cathode, producing a magnetic field by means of the current to be amplified and subjecting the electrons to the action of said magnetic field in such a way thatthey Wlll tend to move in variable spiral lines and a variable number will be intercepted by the grid anode. Y

8. The method of amplifying a variable current which consists in producing an.

of the current to be amplified, and thereby causing the electrons to move in variable spiral lines whereby a variable number will be intercepted by the grid anode.

9. The method of amplifying a variable current which consists in producing an emission of electrons from a cathode to a grid anode and a third electrode surrounding said cathode and subjecting the electrons to the action of a magnetic field produced by thecurrent to be amplified in a direction parallel to said cathode.

10. In combination, an electron discharge device comprising an evacuated envelop containing a cathode,'an anode surrounding said cathode and a third electrodesurrounding said anode, means for impressing a definite positive potential upon the anode, means for impressing a smaller positive potential upon the third electrode, and means for producing a magnetic field in a direction parallel to said cathode.

11. In combination, an electron discharge device comprising a plurality of electrodes inclosed in a highly evacuated receptacle and having sources of potential applied to said electrodes in such a way that the device has a working range over which the current flow sources of potential'applled to said electrodes in such a way that the device has a working range over which the current flow there.- through varies inversely as the potential applied thereto, and means for producing a magnetic field'for controlling the flow of current through said device.

13. In combination, an electron discharge device comprising an electron emitting cathode, an anode, and a third electrode 1nclosed in a highly evacuated receptacle, sources of potential applied to said electrodes in such a way that the device has a working range over which the current flow from the cathode to the third electrode varies inversely as the potential applied thereto, and means for roducing a magnetic field for controlling t e current flow from the cathode and a third electrode surrounding said anode sources of potential applied to said electrodes in such a way that the device has a working range over whichthe current flow from the cathode to the third electrode vanes inversely as the potential applied thereto, andv means for producing a magnetic field for controlling the flow of current from cathode to third electrode.

15. In combinatiom'an electron discharge device comprising an electron emitting cathode, an anode and a third electrode inclosed in a highly evacuated envelop, means for producing a flow of primary electrons operating electrodes inclosed in an evacuated receptacle, and being operable as a negative resistance by electron currents independently of any appreciable gas ionization, and means for producing by the current to be amplified a magnetic field forcontrolling the currentthrough said negative resistance.

17. Means for amplifying a variable current comprising a negative resistance de-' vice, a magnetizing coil surrounding saidv device, and means for supplying the current to be amplified to said magnetizing coil, said negative resistance device comprising an electron emitting'cathode, and cooperating electrodes in an evacuated receptacle, and being operable as a. negative-resistance by electron current independently of any appreciable gas ionization.

18. Means for amplifying'a variable current comprising a negative resistance device having an electron emitting cathode and cooperating electrodes in an evacuated receptacle and operable as a negative resistance by electron current independently ofany appreciable gas ionization and having a Working range over which the current flow therethrough increases and decreases inversely as the potential applied thereto, a magnetizing coil surrounding said receptacle for producing a magnetic field therein, and means for energizing said magnetic coil by the current to be amplified.

19. Means for amplifying a variablecurrent comprising a negative resistance device having a electron emitting cathode, an. anode and a third electrode inclosed in a highly evacuated envelop and having a working range over which the current flow from the cathode to the third electrode varies inversely as to the potential applied thereto, and means for subjecting the electrons flowing from said cathode to the action of a magnetic field produced by the current which is to be amplified.

20. Means for amplifying a variablecurrent comprising a negative resistance device having an electron emitting cathode, an

anode and a third electrode inclosed ina; highly evacuated envelop and having .a'

working ran e over which the current flow.

from the cat ode to the third electrode varies'inversely as the potential applied thereto, a magnetizing coil surrounding said device and means for exciting the coil by the current to be amplified.

21. Means for amplifying a variable current comprising a negative resistance device having an electron emitting cathode, an

anode and a third electrode near the anode and so positioned with respect to the cathode and anode that it will receive electrons from the cathode when it is more positive than the cathode, and that secondary electrons given off from the third electrode can readily reach the anode, and means for producing by the current to be amplified a magnetic field in a direction parallel to said cathode.

22. Means for amplifying avariable current comprising anelectron discharge device having an electron emitting cathode, an anode and a third electrode, means for producing a flow of primary electrons to said third electrode and thereby producing an emission of secondary electrons from said third electrode, and means for producing by the current to be amplified a magnetic field for varying the number of primary electrons which can reach the third electrode.

23. The method of amplifying a variable current which consists in produclng an emission of electrons from a heated cathode to an electrode surrounding said cathode, producing a magnetic field by means of the current to be amplified and subjecting the electrons to the'action of said magnetic field in such a way that the number of electrons reaching said electrode which surrounds the cathode will vary in accordance with variations in the current to be amplified.

24. The method of amplifying a variable current which consists in producing an emission of electrons from a heated cathode to an electrode surrounding the cathode, producing a magnetic field in a direction parallel to said cathode by means of the current to be amplified, and thereby causing the electrons to move in variable spiral lines in such a way that a variable number will reach the electrode surrounding the cathode:

25. The method of amplifying a variable current which consists in producing an emission of electrons from a linear heated cathode to an electrode surrounding said cathode and coaxial therewith, and subjecting the electrons to the action of a magnetic field produced by the current to be amplified in a direction parallel to said cathode. Y

26. In combination, an electron discharge device comprising a linear filamentary cathode adapted to be heated to incandescence to emit electrons, and an electrode surrounding said cathode and coaxial therewith inclosed gin anevacuated envelop, means for producing aflow of electrons from said cathode to said electrode surrounding said cathode, and means for producing a variable magnetic field in a direction parallel to said cathode and thereby varying the number of electrons which will reach said electrode from said cathode.

27. Means for amplifying a variable electric current-comprising an electron discharge device having a linear filamentary cathode adapted to be heated to incandescence to emit electrons, an electrode surrounding said cathode and coaxial therewith, means for producing a magnetic field by the current to be amplified and means for subjecting'the electrons emitted by said cathode to the action of said magnetic field in such a way that the number of electrons reaching the electrode which surrounds said cathode will vary in accordance with variations in the current to be am lified.

28. cans for amplifying a variable current comprising an electron discharge device having a filamentary cathode adapted to beheatedto incandescence to emit electrons, an electrode surrounding said cathode and c0- axial therewith and means for producing by the current to be amplified a magnetic field in a direction parallel to said cathode and thereby causing the electrons emitted by said cathode to move in variable spiral lines in such a Way that a variable. number will reach the electrode surrounding the cathode.

29. Means for amplifying a variable electric current comprising an electron discharge device having a linear cathode adapted to be heated to incandescence to emit electrons, an electrode surrounding said cathode and coaxial therewith and means 'for producing by the current to be amplified a magnetic field in a direction parallel to said cathode.

30. The method of operating an electron discharge device comprising an electron emitting cathode, a grid electrode surrounding said cathode and a third electrode surrounding said cathode and grid electrode which consists in producing a variable magnetic field in a direction parallel to said cathode and thereby varying the current flow from said cathode to said third electrode.

31. The methodof operating an electron discharge device comprising an electron emitting cathode, a grid electrode and a.

third electrode surrounding said cathode and grid electrode, which consists in producing oscillations by means of said device and varying the amplitude of the oscillations produced by producing a variable magnetic field in a direction parallel to said cathode.

32. The method of amplifying a variable current which consists in producing an emission of electrons from a cathode in such a way that part of said electrons will pass through a grid electrode to a third electrode surrounding the cathode and grid electrode,

and subjecting the electrons to the action of a magnetic field produced by the current to be amplifiedin a direction parallel to said cathode.

33. In combination, an electron discharge device comprising a filamentary cathode adapted to be heated to incandescence to emit electrons, a grid electrode adjacent said cathode and a third electrode surrounding said cathode and grid electrode, and means for producing a variable magnetic field in a direction parallel to said cathode and thereby varying the number of electrons which will reach said third electrode from said cathode.

34. Means for amplifying a variable electric current comprising an electron discharge device having a filamentary cathode adapted to be heated to incandescence to emit electrons, a grid electrode adjacent said cathode and a third electrode surrounding said cathode, means for producing a magnetic field by the current to be amplified, and means for subjecting the electrons emitted by said cathode to the action of said magnetic field in such a way that the number of electrons reaching the third electrode will vary in accordance with variations in the current to be amplified.

35. Means for amplifying a. variable electric current comprising an electron discharge device having a linear cathode adapted to be heated to incandescence to emit electrons, a grid electrode adjacent said cathode and a third electrode surrounding said cathode and grid electrode, and means for producing by the current to be'amplified a magnetic field in a direction parallel to said cathode.

36. In combination, an electron discharge device comprising a filamentary cathode adapted to be heated to incandescence to emit electrons, a grid electrode adjacent said cathode and a third electrode surrounding said cathode and grid electrode, means for causing said device to produce oscillations, and means for producing a varying magnetic field in a direction parallel to said cathode and thereby varying the amplitude of the oscillations produced.

37. In combination, an electron discharge device comprising a plurality of electrodes inclosed in a highly evacuated receptacleand having sources of potential applied to sald electrodes in such a way that the device has a Working range over which the current flow increases and decreases inversely as the potential applied thereto, and means forpro- 'ducing a magnetic field in a direction substantially at a right angle to the electrostatic field between the electrodes.

38. In combination, an electron discharge device comprising txvo electrodes one of which is adapted to emit electrons independently of gas ionization and one of which surrounds the other, a conducting grid inter- -netic field in a direction substantially at a right angle to the electrostatic field between the electrodes.

39. In combination, an electron discharge device comprising a plurality of electrodes inclosed in an evacuated receptacle, at least one of said electrodes being adapted to emit electrons independently of gas ionization, sources of potential of such a value and applied to said electrodes in such a way that the device has a working range over which the current flow therethrough increases and decreases inverselyas the potential applied thereto, and means for producin a magnetlc field for controlling the current etween said electrodes.

40. In combination, an electron discharge device comprising a cathode and a cooperating electrode inclosed in an evacuated receptacle and arranged in circular symmetry to each other about an axis, said cathode being adapted to emit electrons independently of gas ionization, means for producing a fiow of current between said electrodes, and means for producing a variable magnetic field in a direction parallel to the axis of symmetry of said electrodes and thereby varyin the current between said electrodes.

41. n combination, an electron discharge device comprising a cathode adapted to emit electrons independently of gas ionization and a coiiperating electrode inclosed in an evacuated receptacle, means for producing a flow of electrons between said electrodes, said electrodes being so arranged with respect to each other that the electrons will tend to move in substantially radial paths between the electrodes, and means for producing a variable magnetic field in the-space between said electrodes in a direction substantially at a right angle to the paths of the electrons.

42. Means for amplifying a variable electric current comprising an electron discharge device having a plurality of electrodes inclosed in an evacuated receptacle and arranged in circular symmetry to each other about an axis, at least one of said electrodes being adapted to emit electrons independently of gas ionization, means for producing a flow of current between said electrodes, and means for producing a magnetic field by the current to be amplified, and for subjecting the electrons emitted by said cathode to the action of said magnetic field in such a way that the current between said electrodes will vary in accordance with variations in a the current to be amplified.

43. Means for amplifying a variable electric current comprising an electron discharge device having a cathode adapted to emit electrons independently of gas ionization and a cooperating electrode inclosed in an evacuated receptacle, means for producing thereby varying the current carried by. the

electrons between the electrodes in accordance with variations in the current to be amplified.

44. In combination, an electron discharge device comprising a cathode adapted to emit electrons independently of gas ionization and a cooperating electrode surrounding said cathode and arranged in circular symmetry with respect to said cathode about an axis, means for producing a flow of current between said electrodes, and means for producing a variable magnetic field in a direction parallel to the axis of symmetry. of said electrodes and thereby varying the flow of current between the electrodes.

45. Means for producing and controlling high frequency oscillations comprising an electron discharge device having a cathode and a ,cotiperating electrode inclosed in an evacuated receptacle, means for producing a flow of electrons between said electrodes, said electrodes being so arran ed with respect to each other that the e ectrons will tend to move in substantially radial paths between the electrodes, an oscillating circuit associated with said electrodes and means for producing a variable magnetic field in the space between said electrodes in a direction substantially at a right angle to the paths of the electrons.

46. Means for producing and controlling high frequency oscillations comprising an electron discharge device having a cathode and a cooperating electrode inclosed in an evacuated receptacle and arranged in circular symmetry to each other about an axis, an oscillating circuit associated with said electrodes, means for producing a flow of electrons between said electrodes and means for producing and varying a'magnetic field in a direction parallel to the axis of symmetry of said electrodes and thereby producing a corresponding variation in the flow of electrons between said electrodes.

47. Means for producing and controlling high frequency currents comprising an electron discharge device having an electron emitting cathode and a coiiperating electrode surrounding said cathode, and arranged in circular symmetry to said cathode about an axis, an oscillating circuit associated withsaid electrodes, means for producing a flow of electrons between sald electrodes and means for producing'and varying a ma etic field in a directlon parallel to the axis of symmetry of said electrodes and thereb producing a corresponding variation in t e flow of electrons between said electrodes. i

48. The method of operatin an electron discharge device having a cat ode adapted -to emit electrons independently of gaslonization and a coiiperating electrode inclosed in an evacuated receptacle, which consists in producing aoflow of electrons in substantially radial paths between said electrodes and producing a variable magnetic. field in the spacebetween said electrodes in'a direction substantially 'at a right angle to the paths of the electrons, and thereby varying" tia ly radial paths between said electrodesand producing a magnetic field in the space between the. electrodes by the current :to be amplified,- therebycausing the current between said electrodes to varyin accordance with variations the current to be' ampli- 50. I method of operating an electron discharge device compri a cathode adapted to emit electrons iilfipendently of gas ionization and a cooperating electrodeinclosed' in an: evacuated receptacle 'for 'am-v plifym a variable current, which consists;

in ro ucing a flow of electrons in s'ubstantia radial paths between said electrodes, pr uclng by means of the current tobe amplified a magnetic field --in a direction substantially at a right angle to the paths of the electrons, and subjecting the electrons tothe action of said magnetic field thereby varying their paths in such a wa that the current between the electrodes w vary in accordance with variations'in the magnetic 51,,The method of operating an electron discharge device having an electron emitting cathode and .a cofiperating electrode m closed in an evacuated receptacle, and havin an osc1llatory circu1t associated w th, sa1d electrodes, wh1ch conslsts 1n produclng a flow-of electrons ,between said electrodes, producing high frequency oscillations in said oscillatory circuit, producing. a magnetic field in a direction substantially at a right angle to the paths of said electrons, and varying the'strength of said magnetlc field and thereby varying the amplitude of the high frequency oscillations produced in said oscillating circuit;

52. The combmatlon m a high frequency signaling system of an. electron dlschar associated with said electrodes in such a way that high frequency oscillations will be produced in said oscillatory circuit, means for producing a magnetic field in the space between said. electrodes, and means for varydevice having an electron emitting catho e Y and a cofiperating electrode inclosed n an evacuated receptacle, an oscillatory c1rcu1t ihg the strength of said magnetic field 1n accordance with variations in a signaling current and thereby varying the amplitude of the high frequency'oscillations produced I i in said oscillatory circuit.

53. Th combination in a signaling system of an electron discharge device having a cathode and a coiiperatmg electrode in- .closed in an evacuated 'rece tacle, an oscil la' tory circuit associated wit said electrodes insuch' a Way that h hfrequency oscillationswill be produce said oscillatory circuitfi-mems for producing a magnetic field inn-the space between said electrodes,

and mcansjfdr varying thejstrength' of said maguetic field in accordance with variations in, sound waves, thereby l 1roducing--afcorresponding variation ;in-- e amplitude of the said oscillatory circuit.

In witness whereof,

myahand this 11th day ofNovember, -1916.

ALBERT vW. HULL.

I have. hereunto frequency oscillations produced 

